Facile Synthesis of Cadmium Doped Graphite Carbon Nitride for Photocatalytic Degradation of Tetracycline Under Visible Light Irradiation

Abstract

Using semiconductor photocatalysts for antibiotic contaminants degradation under visible light has become a hot topic in recent years. Herein, a novel and ingenious cadmium doped graphite phase carbon nitride (Cd-g-C3N4) photocatalyst was successfully constructed via 60°C oil bath method to degrade tetracycline. Experimental and characterization results revealed that cadmium was well doped at g-C3N4 surface and exhibited high intercontact with g-C3N4. Additionally, the introduction of cadmium significantly improved the photocatalytic activity, and the optimum degradation efficiency of 10-Cd-g-C3N4 reached to 98.1%, which was exceeded 2.0 times than pure g-C3N4 (43.9%). Meanwhile, the 10-Cd-g-C3N4 sample presented higher electrical conductivity, light absorption property and photogenerated electron-hole pairs migration compared with bare g-C3N4. Additionally, the quenching experiments and electron spin-resonance tests were exhibited holes (h+), hydroxyl radicals (•OH) and superoxide radicals (•O2−) were main active species involved in TC degradation. Equally, the effects of various conditions on photocatalytic efficiency, such as pH, initial TC concentrations and catalyst dosage, were also researched. This work gives a reasonable point to synthesize high-efficiency and economic photocatalysts.